if you mess with the United States, there will be hell toupee."
or
Because they don't fit on a ironing board
or
None, because people who glow in the dark don't need light bulbs.
Note: Topical to the Chernobyl Reactor disaster of 1984.
or
Five. One to change the bulb and eleven to say they could do it faster.
or
Because it would fall over if it lifted the other one.
or